MOUND LABORATORY PROGRESS REPORT FOR JUNE 1963

3 8 ; 9 4 5 7 5 C 9 E ; < : 7over a 1456-day period. The half life was calculated to be 12.355 plus or minus 0.0l0 years, based on measurements in three calorimeters. The yields of /sup 208/Po and /sup 209/Po from the irradiation of multicurie quantities of /sup 210/Po were calculated. Production of small quantities of /sup 208/Po and /sup 209/Po is possible by the (n,xn) reaction; however, large quantities of /sup 210/Po would be present in the /sup 208/Po--/sup 209/Po sample. On the basis of these calculations the maximum /sup 208/Po content would occur after 466 days' irradiation in the materials testing reactor. An experimental decay scheme was drawn for /sup 208/Po on the basis of experimental data. Experiments are in progress to determine whether levels at about 1.4 Mev in /sup 208/Bi are populated in the electron capture decay of /sup 208/Po The known half-life method for determining the resolution time of a counting instrument was found to yield only an average value for the counting range in the computation. To correct the counting error a series of computations should be made with data covering only a short segment of the decay curve rather than a single computation covering the entire range. Alternatively, the decayingpair method of half life determination can be used, eliminating the need for an accurate knowledge of the resolution time. A process for the separation of /sup 234/U from /sup 238/Pu was developed. One batch of feed solution was processed by the method, and 14 mg of / sup 234/U were recovered. A second continuous solvent extraction process is being investigated. Thermogravimetric studies and the differential thermal analysis of potassium plutonium suifate dihydrate were completed. The previously reported DTA thermogram for salt was confirmed. The existence of the complex acid H/sub 2/Pu(SO/sub 4/)4 is indicated. The solubility of potassium plutonium sulfate dihydrate was determined in solutions of 0.959 M H/sub 2/SO/sub 4/ containing potassium chloride at concentrations from 0.1 to 0.5 M. The values were plotted in a straight line with a slope of 4.08, as compared to a theoretical 4.00. A thermogravimetric analysis of potassium plutonium sulfate dihydrate was completed. Thermograrns of this dihydrate and of plutonium sulfate tetrahydrate indicated that a crystalline phase transformation occurs after the waters of hydration are driven off. The potassium sulfate alpha-to-beta phase transformation was absent from the dihydrate salt thermogram indicating that no free potassium sulfate was present. Two cascaded, 24-foot, hot-wire thermal diffusion columns are being used to remove heavy gaseous impurities, such as nitrogen, carbon monoxide, and ethane, from 99% pure natural methane. In a three- column series system the /sup 13/C content is 7% in 89% methane at the bottom of the third stage. The first five stages of a seven-stage thermal diffusion column cascade system enriched natural methane to about l0% /sup 13/C. Thermal diffusion column transport coefficients are being measured for various carbon monoxide masses, and an accurate value is being determined for the experimental hot wall temperature. An experimental system is being designed for studying the nonaqueous carbamate chernical exchange method for enriching /sup 13/C. The system is expected to yield a separation factor up to 1.39, although about 100 hours is required for equilibrium. The use of alternating current for heating column center wires is being studied. A 36-inch wire was attached to a wooden frame, while the bottom of the wire was allowed to swing freely in a pool of mercury. At 48 amperes and 24 volts the wire was deflected to the side of the mercury container; a larger container lessened the deflection. A magnetic field between the lead wire and the center wire may also increase deflection. The equation describing the steady state vibrations of column wire heated by alternating current was derived. To date, the maximum amount of polonium that could be contained by electroplated gold was 5 to 10 mC/cm/sup 2/. By another procedure the maximu